Various workers have noted that certain compounds and compositions containing hydrogen groups on silicon atoms (SiH groups) can impart a measure of corrosion resistance to metals under particular circumstances. This observation has been documented in such patents as U.S. Pat. No. 3,397,046 to Greyson, in which an organohydrogenpolysiloxane is heat cured on a silver coated copper conductor and then overcoated with a polymeric insulating layer. Likewise. U.S. Pat. No. 3,069,451 to Fritz mentions that certain SiH-containing silanes prepared according to his method can form laquer-like coatings which can be utilized for anti-rust purposes. De Monterey, in U.S. Pat. No. 3,450,736. reacted SiH-functional polysiloxanes with an ethylenically unsaturated compound to obtain a modified polymer having good lubricating and corrosion inhibition properties. Wright, in U.S. Pat. No. 3,145,175, discloses a grease composition which provides improved corrosion resistance to metals, which composition is a thickened copolymer containing SiH groups or a thickened mixture of a diorganopolysiloxane and an organohydrogenpolysiloxane. Japanese Kokai (Laid Open) 56-145111 to Asahi Chemical Industry Company teaches rust-preventing pigments comprising microparticulated hydrogenated silicon which can be added to paint formulations.
U.S. Pat. No. 4,701,380 to Narula et al. discloses curable compositions which provide corrosion protection to metals. These compositions are based on a hydroxy-terminated diorganopolysiloxane polymer and contain either a reaction product or blend of a resinous copolymeric siloxane and a liquid organohydrogenpolysiloxane in addition to an organosilane which promotes adhesion to substrates. Similar compositions, which are specifically designed to be applied by spraying, are also taught in U.S. Pat. No. 5.051.311 to Popa et al. European Patent Application 0299641 (published on Jan. 18, 1989) to Dow Corning Corporation discloses curable compositions which provide corrosion protection to metals. These compositions are similar to those of the above cited patent to Narula et al. and are also based on a combination of a hydroxy-terminated diorganopolysiloxane polymer and either a reaction product or blend of a resinous copolymeric siloxane and a liquid organohydrogenpolysiloxane but attribute improved corrosion performance to the addition of alumina or hydrates of alumina.
The use of SiH-containing compounds is also known in compositions which promote adhesion between silicone materials and various other substrates. For example, Hamada et al., in U.S. Pat. No. 4,332,844, teach primer compositions for silicone rubbers containing an alkoxy-functional silicon compound, an organotitanate and an organohydrogensilicon compound. In Kolloidn. Zr. (Colloid Journal), 32(2), p. 401-403 (1975), Rudoi et al. studied the kinetics of bond formation between a glass surface and a hydroxy-terminated filled polydimethylsiloxane containing a crosslinker/adhesion promoter which was a product of hydrolytic condensation of tetraethoxysilane with oligomeric polydiethylethylhydrogensiloxane.
Although the above references may invite further experimentation with various SiH-containing compounds or compositions for the purpose of improving adhesion or corrosion resistance in other systems, there is no suggestion provided by this art as to the possible benefit to expect in any particular system. In other words, there is no practical guidance provided in the above literature that would lead the skilled artisan to reliably predict additional compositions which could be advantageously modified to obtain the desired properties.